/Engine/Plugins/Runtime/GameplayAbilities/Source/GameplayAbilities/Public/AbilitySystemBlueprintLibrary.h
Returns the total duration for a given GameplayEffect, basically ExpectedEndTime - Current Time
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Ability|GameplayEffect", Meta=(WorldContext="WorldContextObject")) static float GetActiveGameplayEffectRemainingDuration ( [UObject](API\Runtime\CoreUObject\UObject\UObject) * WorldContextObject, [FActiveGameplayEffectHandle](API\Plugins\GameplayAbilities\FActiveGameplayEffectHandle) ActiveHandle )